/**
 * SceneManager类 
 * 场景管理器
 * 切换场景
 */
(function(window) {
	let SceneManager = window.SceneManager = function() {
		this.curScene = 1	//当前场景
		//实例化场景
		this.scene1 = new Scene1()
		this.scene2 = new Scene2()
		this.scene3 = new Scene3()
	}
	
	//更新
	SceneManager.prototype.update = function() {
		this['scene'+this.curScene].update && this['scene'+this.curScene].update()
	}
	
	//渲染
	SceneManager.prototype.render = function() {
		this['scene'+this.curScene].render()
	}
})(window)